/*
 * Copyright 2002-2013 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package cn.cloud.all.security.web;

import org.springframework.web.servlet.support.RequestDataValueProcessor;

import javax.servlet.http.HttpServletRequest;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Pattern;

public final class CsrfRequestDataValueProcessor implements RequestDataValueProcessor {
    private Pattern DISABLE_CSRF_TOKEN_PATTERN = Pattern.compile("(?i)^(GET|HEAD|TRACE|OPTIONS)$");

    private String DISABLE_CSRF_TOKEN_ATTR = "DISABLE_CSRF_TOKEN_ATTR";

    public String processAction(HttpServletRequest request, String action) {
        return action;
    }

    public String processAction(HttpServletRequest request, String action, String method) {
        if (method != null && DISABLE_CSRF_TOKEN_PATTERN.matcher(method).matches()) {
            request.setAttribute(DISABLE_CSRF_TOKEN_ATTR, Boolean.TRUE);
        } else {
            request.removeAttribute(DISABLE_CSRF_TOKEN_ATTR);
        }
        return action;
    }

    public String processFormFieldValue(HttpServletRequest request, String name, String value, String type) {
        return value;
    }

    public Map<String, String> getExtraHiddenFields(HttpServletRequest request) {
        if (Boolean.TRUE.equals(request.getAttribute(DISABLE_CSRF_TOKEN_ATTR))) {
            request.removeAttribute(DISABLE_CSRF_TOKEN_ATTR);
            return Collections.emptyMap();
        }

        CsrfToken token = (CsrfToken) request.getAttribute(CsrfToken.class.getName());
        if (token == null) {
            return Collections.emptyMap();
        }
        Map<String, String> hiddenFields = new HashMap<>(1);
        hiddenFields.put(token.getParameterName(), token.getToken());
        return hiddenFields;
    }

    public String processUrl(HttpServletRequest request, String url) {
        return url;
    }
}
